free to go

I'm triyng this search engine as an alternative to google.http://duckduckgo.com/
also available a plugin for firefox:https://addons.mozilla.org/en-US/firefox/search/?q=duckduckgo&appver=13.0&platform=linux
from wikipedia:The search engine policy emphasizes privacy and does not record
user information...With users free from being profiled, this search method
effectively breaks out of "the filter bubble" so that all users
are given the same search results, not a set that has been
tailored (filtered) to what the engine thinks the individual user
wants to see...Some of the code of DuckDuckGo is free software distributed at
GitHub under Perl 5 license.

DuckDuckGo is good and has some nice features like typing "!so perl linux" will search stack overflow for perl and linux.
There are many many predefined !bang words.

Disadvantages:

- Just like Google it seems to prefer to put wikipedia entries on top (which I am generally not interested in, I would have searched on Wikipedia myself first)
- It's based on Bing mostly and they are just not as good as Google.

That said, I have used DDG now for almost 2 years and removed Google from all my shortcuts, surely they are doing fine.